Comparative biomechanical study of cervical spine stabilisation by cage alone, cage with plate, or plate-cage: a porcine model.

PURPOSE To compare stability and subsidence associated with 3 types of cervical spine stabilisation. METHODS The C3 to C4 vertebrae of 28 Polish pigs were used. Pigs with intact vertebrae (group 1) underwent standard anterior cervical discectomy (group 2), followed by stabilisation using a cage alone (group 3), a cage with plate (group 4), or a plate-cage (group 5). Cervical spine stability and subsidence were compared in all 5 groups. RESULTS Stability was significantly increased after stabilisation by a cage with plate or a plate-cage, but not by a cage alone. The difference between stabilisation by a cage with plate and a plate-cage was not significant. Subsidence was maximal after the cage-alone stabilisation (3.1 mm), being 1.6 mm after the cage-with-plate and plate-cage stabilisations. CONCLUSION Additional plating as a supplement to anterior interbody cervical cage stabilisation significantly improves segmental stability and subsidence.